Repulsive interaction and contrast inversion in noncontact atomic force microscopy imaging of adsorbates
Repulsive interaction and contrast inversion in noncontact atomic force microscopy imaging of adsorbates
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DOI：
10.1103/physrevb.77.195410
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发表时间：
2008-05-01
影响因子：
3.7
通讯作者：
Kuehnle, A.
中科院分区：
文献类型：
--
作者：
Rahe, P.;Bechstein, R.;Kuehnle, A.
为了理解原子分辨率非接触原子力显微镜(NC-AFM)中的对比度形成，我们研究了针尖与样品之间的排斥相互作用是否有助于对比度的形成。我们根据振荡幅度和测量失谐将吸引和排斥相互作用与对比度特征联系起来。基于Morse势的模拟说明了由于表面吸附上的排斥相互作用而导致的对比度反转背后的机制。云母和二氧化钛表面吸附的NC-AFM实验图像证实了我们的模拟结果。此外，我们还讨论了地形反馈回路对吸附物质上方对比度形成的影响，这表明对于常失谐图像，数据解释可能变得相当精细。
To understand contrast formation in atomic resolution noncontact atomic force microscopy (NC-AFM), we investigate whether or not repulsive tip-sample interaction contributes to contrast formation. We relate attractive and repulsive interactions to contrast features depending on both oscillating amplitude and measured detuning. Simulations based on a Morse potential illustrate the mechanism behind contrast inversion due to repulsive interactions above an adsorbate on the surface. Experimental NC-AFM images of adsorbates on mica and TiO2 surfaces confirm our simulations. Furthermore, we discuss the influence of the topography feedback loop on contrast formation above adsorbates, which illustrates that data interpretation can become rather delicate for constant-detuning images.